@article{ERAAMS_2005_11_a7,
     author = {Stefanov, Plamen and Uhlmann, Gunther},
     title = {Recent progress on the boundary rigidity problem},
     journal = {Electronic research announcements of the American Mathematical Society},
     pages = {64--70},
     publisher = {mathdoc},
     volume = {11},
     year = {2005},
     doi = {10.1090/S1079-6762-05-00148-4},
     url = {http://geodesic.mathdoc.fr/articles/10.1090/S1079-6762-05-00148-4/}
}